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-rw-r--r--sha1_file.c3631
1 files changed, 3631 insertions, 0 deletions
diff --git a/sha1_file.c b/sha1_file.c
new file mode 100644
index 0000000000..d295a3225a
--- /dev/null
+++ b/sha1_file.c
@@ -0,0 +1,3631 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ *
+ * This handles basic git sha1 object files - packing, unpacking,
+ * creation etc.
+ */
+#include "cache.h"
+#include "string-list.h"
+#include "lockfile.h"
+#include "delta.h"
+#include "pack.h"
+#include "blob.h"
+#include "commit.h"
+#include "run-command.h"
+#include "tag.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "refs.h"
+#include "pack-revindex.h"
+#include "sha1-lookup.h"
+#include "bulk-checkin.h"
+#include "streaming.h"
+#include "dir.h"
+
+#ifndef O_NOATIME
+#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
+#define O_NOATIME 01000000
+#else
+#define O_NOATIME 0
+#endif
+#endif
+
+#define SZ_FMT PRIuMAX
+static inline uintmax_t sz_fmt(size_t s) { return s; }
+
+const unsigned char null_sha1[20];
+
+/*
+ * This is meant to hold a *small* number of objects that you would
+ * want read_sha1_file() to be able to return, but yet you do not want
+ * to write them into the object store (e.g. a browse-only
+ * application).
+ */
+static struct cached_object {
+ unsigned char sha1[20];
+ enum object_type type;
+ void *buf;
+ unsigned long size;
+} *cached_objects;
+static int cached_object_nr, cached_object_alloc;
+
+static struct cached_object empty_tree = {
+ EMPTY_TREE_SHA1_BIN_LITERAL,
+ OBJ_TREE,
+ "",
+ 0
+};
+
+/*
+ * A pointer to the last packed_git in which an object was found.
+ * When an object is sought, we look in this packfile first, because
+ * objects that are looked up at similar times are often in the same
+ * packfile as one another.
+ */
+static struct packed_git *last_found_pack;
+
+static struct cached_object *find_cached_object(const unsigned char *sha1)
+{
+ int i;
+ struct cached_object *co = cached_objects;
+
+ for (i = 0; i < cached_object_nr; i++, co++) {
+ if (!hashcmp(co->sha1, sha1))
+ return co;
+ }
+ if (!hashcmp(sha1, empty_tree.sha1))
+ return &empty_tree;
+ return NULL;
+}
+
+int mkdir_in_gitdir(const char *path)
+{
+ if (mkdir(path, 0777)) {
+ int saved_errno = errno;
+ struct stat st;
+ struct strbuf sb = STRBUF_INIT;
+
+ if (errno != EEXIST)
+ return -1;
+ /*
+ * Are we looking at a path in a symlinked worktree
+ * whose original repository does not yet have it?
+ * e.g. .git/rr-cache pointing at its original
+ * repository in which the user hasn't performed any
+ * conflict resolution yet?
+ */
+ if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
+ strbuf_readlink(&sb, path, st.st_size) ||
+ !is_absolute_path(sb.buf) ||
+ mkdir(sb.buf, 0777)) {
+ strbuf_release(&sb);
+ errno = saved_errno;
+ return -1;
+ }
+ strbuf_release(&sb);
+ }
+ return adjust_shared_perm(path);
+}
+
+enum scld_error safe_create_leading_directories(char *path)
+{
+ char *next_component = path + offset_1st_component(path);
+ enum scld_error ret = SCLD_OK;
+
+ while (ret == SCLD_OK && next_component) {
+ struct stat st;
+ char *slash = next_component, slash_character;
+
+ while (*slash && !is_dir_sep(*slash))
+ slash++;
+
+ if (!*slash)
+ break;
+
+ next_component = slash + 1;
+ while (is_dir_sep(*next_component))
+ next_component++;
+ if (!*next_component)
+ break;
+
+ slash_character = *slash;
+ *slash = '\0';
+ if (!stat(path, &st)) {
+ /* path exists */
+ if (!S_ISDIR(st.st_mode))
+ ret = SCLD_EXISTS;
+ } else if (mkdir(path, 0777)) {
+ if (errno == EEXIST &&
+ !stat(path, &st) && S_ISDIR(st.st_mode))
+ ; /* somebody created it since we checked */
+ else if (errno == ENOENT)
+ /*
+ * Either mkdir() failed because
+ * somebody just pruned the containing
+ * directory, or stat() failed because
+ * the file that was in our way was
+ * just removed. Either way, inform
+ * the caller that it might be worth
+ * trying again:
+ */
+ ret = SCLD_VANISHED;
+ else
+ ret = SCLD_FAILED;
+ } else if (adjust_shared_perm(path)) {
+ ret = SCLD_PERMS;
+ }
+ *slash = slash_character;
+ }
+ return ret;
+}
+
+enum scld_error safe_create_leading_directories_const(const char *path)
+{
+ /* path points to cache entries, so xstrdup before messing with it */
+ char *buf = xstrdup(path);
+ enum scld_error result = safe_create_leading_directories(buf);
+ free(buf);
+ return result;
+}
+
+static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
+{
+ int i;
+ for (i = 0; i < 20; i++) {
+ static char hex[] = "0123456789abcdef";
+ unsigned int val = sha1[i];
+ char *pos = pathbuf + i*2 + (i > 0);
+ *pos++ = hex[val >> 4];
+ *pos = hex[val & 0xf];
+ }
+}
+
+const char *sha1_file_name(const unsigned char *sha1)
+{
+ static char buf[PATH_MAX];
+ const char *objdir;
+ int len;
+
+ objdir = get_object_directory();
+ len = strlen(objdir);
+
+ /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
+ if (len + 43 > PATH_MAX)
+ die("insanely long object directory %s", objdir);
+ memcpy(buf, objdir, len);
+ buf[len] = '/';
+ buf[len+3] = '/';
+ buf[len+42] = '\0';
+ fill_sha1_path(buf + len + 1, sha1);
+ return buf;
+}
+
+/*
+ * Return the name of the pack or index file with the specified sha1
+ * in its filename. *base and *name are scratch space that must be
+ * provided by the caller. which should be "pack" or "idx".
+ */
+static char *sha1_get_pack_name(const unsigned char *sha1,
+ char **name, char **base, const char *which)
+{
+ static const char hex[] = "0123456789abcdef";
+ char *buf;
+ int i;
+
+ if (!*base) {
+ const char *sha1_file_directory = get_object_directory();
+ int len = strlen(sha1_file_directory);
+ *base = xmalloc(len + 60);
+ sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
+ sha1_file_directory, which);
+ *name = *base + len + 11;
+ }
+
+ buf = *name;
+
+ for (i = 0; i < 20; i++) {
+ unsigned int val = *sha1++;
+ *buf++ = hex[val >> 4];
+ *buf++ = hex[val & 0xf];
+ }
+
+ return *base;
+}
+
+char *sha1_pack_name(const unsigned char *sha1)
+{
+ static char *name, *base;
+
+ return sha1_get_pack_name(sha1, &name, &base, "pack");
+}
+
+char *sha1_pack_index_name(const unsigned char *sha1)
+{
+ static char *name, *base;
+
+ return sha1_get_pack_name(sha1, &name, &base, "idx");
+}
+
+struct alternate_object_database *alt_odb_list;
+static struct alternate_object_database **alt_odb_tail;
+
+/*
+ * Prepare alternate object database registry.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * alternate_object_database. The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is similar to that environment variable but can be
+ * LF separated. Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold 40-byte hex
+ * SHA1, an extra slash for the first level indirection, and the
+ * terminating NUL.
+ */
+static int link_alt_odb_entry(const char *entry, const char *relative_base,
+ int depth, const char *normalized_objdir)
+{
+ struct alternate_object_database *ent;
+ struct alternate_object_database *alt;
+ int pfxlen, entlen;
+ struct strbuf pathbuf = STRBUF_INIT;
+
+ if (!is_absolute_path(entry) && relative_base) {
+ strbuf_addstr(&pathbuf, real_path(relative_base));
+ strbuf_addch(&pathbuf, '/');
+ }
+ strbuf_addstr(&pathbuf, entry);
+
+ normalize_path_copy(pathbuf.buf, pathbuf.buf);
+
+ pfxlen = strlen(pathbuf.buf);
+
+ /*
+ * The trailing slash after the directory name is given by
+ * this function at the end. Remove duplicates.
+ */
+ while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
+ pfxlen -= 1;
+
+ entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
+ ent = xmalloc(sizeof(*ent) + entlen);
+ memcpy(ent->base, pathbuf.buf, pfxlen);
+ strbuf_release(&pathbuf);
+
+ ent->name = ent->base + pfxlen + 1;
+ ent->base[pfxlen + 3] = '/';
+ ent->base[pfxlen] = ent->base[entlen-1] = 0;
+
+ /* Detect cases where alternate disappeared */
+ if (!is_directory(ent->base)) {
+ error("object directory %s does not exist; "
+ "check .git/objects/info/alternates.",
+ ent->base);
+ free(ent);
+ return -1;
+ }
+
+ /* Prevent the common mistake of listing the same
+ * thing twice, or object directory itself.
+ */
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ if (pfxlen == alt->name - alt->base - 1 &&
+ !memcmp(ent->base, alt->base, pfxlen)) {
+ free(ent);
+ return -1;
+ }
+ }
+ if (!strcmp_icase(ent->base, normalized_objdir)) {
+ free(ent);
+ return -1;
+ }
+
+ /* add the alternate entry */
+ *alt_odb_tail = ent;
+ alt_odb_tail = &(ent->next);
+ ent->next = NULL;
+
+ /* recursively add alternates */
+ read_info_alternates(ent->base, depth + 1);
+
+ ent->base[pfxlen] = '/';
+
+ return 0;
+}
+
+static void link_alt_odb_entries(const char *alt, int len, int sep,
+ const char *relative_base, int depth)
+{
+ struct string_list entries = STRING_LIST_INIT_NODUP;
+ char *alt_copy;
+ int i;
+ struct strbuf objdirbuf = STRBUF_INIT;
+
+ if (depth > 5) {
+ error("%s: ignoring alternate object stores, nesting too deep.",
+ relative_base);
+ return;
+ }
+
+ strbuf_add_absolute_path(&objdirbuf, get_object_directory());
+ normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
+
+ alt_copy = xmemdupz(alt, len);
+ string_list_split_in_place(&entries, alt_copy, sep, -1);
+ for (i = 0; i < entries.nr; i++) {
+ const char *entry = entries.items[i].string;
+ if (entry[0] == '\0' || entry[0] == '#')
+ continue;
+ if (!is_absolute_path(entry) && depth) {
+ error("%s: ignoring relative alternate object store %s",
+ relative_base, entry);
+ } else {
+ link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
+ }
+ }
+ string_list_clear(&entries, 0);
+ free(alt_copy);
+ strbuf_release(&objdirbuf);
+}
+
+void read_info_alternates(const char * relative_base, int depth)
+{
+ char *map;
+ size_t mapsz;
+ struct stat st;
+ char *path;
+ int fd;
+
+ path = xstrfmt("%s/info/alternates", relative_base);
+ fd = git_open_noatime(path);
+ free(path);
+ if (fd < 0)
+ return;
+ if (fstat(fd, &st) || (st.st_size == 0)) {
+ close(fd);
+ return;
+ }
+ mapsz = xsize_t(st.st_size);
+ map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+
+ link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
+
+ munmap(map, mapsz);
+}
+
+void add_to_alternates_file(const char *reference)
+{
+ struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
+ char *alts = git_pathdup("objects/info/alternates");
+ FILE *in, *out;
+
+ hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
+ out = fdopen_lock_file(lock, "w");
+ if (!out)
+ die_errno("unable to fdopen alternates lockfile");
+
+ in = fopen(alts, "r");
+ if (in) {
+ struct strbuf line = STRBUF_INIT;
+ int found = 0;
+
+ while (strbuf_getline(&line, in, '\n') != EOF) {
+ if (!strcmp(reference, line.buf)) {
+ found = 1;
+ break;
+ }
+ fprintf_or_die(out, "%s\n", line.buf);
+ }
+
+ strbuf_release(&line);
+ fclose(in);
+
+ if (found) {
+ rollback_lock_file(lock);
+ lock = NULL;
+ }
+ }
+ else if (errno != ENOENT)
+ die_errno("unable to read alternates file");
+
+ if (lock) {
+ fprintf_or_die(out, "%s\n", reference);
+ if (commit_lock_file(lock))
+ die_errno("unable to move new alternates file into place");
+ if (alt_odb_tail)
+ link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
+ }
+ free(alts);
+}
+
+int foreach_alt_odb(alt_odb_fn fn, void *cb)
+{
+ struct alternate_object_database *ent;
+ int r = 0;
+
+ prepare_alt_odb();
+ for (ent = alt_odb_list; ent; ent = ent->next) {
+ r = fn(ent, cb);
+ if (r)
+ break;
+ }
+ return r;
+}
+
+void prepare_alt_odb(void)
+{
+ const char *alt;
+
+ if (alt_odb_tail)
+ return;
+
+ alt = getenv(ALTERNATE_DB_ENVIRONMENT);
+ if (!alt) alt = "";
+
+ alt_odb_tail = &alt_odb_list;
+ link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
+
+ read_info_alternates(get_object_directory(), 0);
+}
+
+/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
+static int freshen_file(const char *fn)
+{
+ struct utimbuf t;
+ t.actime = t.modtime = time(NULL);
+ return !utime(fn, &t);
+}
+
+/*
+ * All of the check_and_freshen functions return 1 if the file exists and was
+ * freshened (if freshening was requested), 0 otherwise. If they return
+ * 0, you should not assume that it is safe to skip a write of the object (it
+ * either does not exist on disk, or has a stale mtime and may be subject to
+ * pruning).
+ */
+static int check_and_freshen_file(const char *fn, int freshen)
+{
+ if (access(fn, F_OK))
+ return 0;
+ if (freshen && !freshen_file(fn))
+ return 0;
+ return 1;
+}
+
+static int check_and_freshen_local(const unsigned char *sha1, int freshen)
+{
+ return check_and_freshen_file(sha1_file_name(sha1), freshen);
+}
+
+static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
+{
+ struct alternate_object_database *alt;
+ prepare_alt_odb();
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ fill_sha1_path(alt->name, sha1);
+ if (check_and_freshen_file(alt->base, freshen))
+ return 1;
+ }
+ return 0;
+}
+
+static int check_and_freshen(const unsigned char *sha1, int freshen)
+{
+ return check_and_freshen_local(sha1, freshen) ||
+ check_and_freshen_nonlocal(sha1, freshen);
+}
+
+int has_loose_object_nonlocal(const unsigned char *sha1)
+{
+ return check_and_freshen_nonlocal(sha1, 0);
+}
+
+static int has_loose_object(const unsigned char *sha1)
+{
+ return check_and_freshen(sha1, 0);
+}
+
+static unsigned int pack_used_ctr;
+static unsigned int pack_mmap_calls;
+static unsigned int peak_pack_open_windows;
+static unsigned int pack_open_windows;
+static unsigned int pack_open_fds;
+static unsigned int pack_max_fds;
+static size_t peak_pack_mapped;
+static size_t pack_mapped;
+struct packed_git *packed_git;
+
+void pack_report(void)
+{
+ fprintf(stderr,
+ "pack_report: getpagesize() = %10" SZ_FMT "\n"
+ "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
+ "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
+ sz_fmt(getpagesize()),
+ sz_fmt(packed_git_window_size),
+ sz_fmt(packed_git_limit));
+ fprintf(stderr,
+ "pack_report: pack_used_ctr = %10u\n"
+ "pack_report: pack_mmap_calls = %10u\n"
+ "pack_report: pack_open_windows = %10u / %10u\n"
+ "pack_report: pack_mapped = "
+ "%10" SZ_FMT " / %10" SZ_FMT "\n",
+ pack_used_ctr,
+ pack_mmap_calls,
+ pack_open_windows, peak_pack_open_windows,
+ sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
+}
+
+/*
+ * Open and mmap the index file at path, perform a couple of
+ * consistency checks, then record its information to p. Return 0 on
+ * success.
+ */
+static int check_packed_git_idx(const char *path, struct packed_git *p)
+{
+ void *idx_map;
+ struct pack_idx_header *hdr;
+ size_t idx_size;
+ uint32_t version, nr, i, *index;
+ int fd = git_open_noatime(path);
+ struct stat st;
+
+ if (fd < 0)
+ return -1;
+ if (fstat(fd, &st)) {
+ close(fd);
+ return -1;
+ }
+ idx_size = xsize_t(st.st_size);
+ if (idx_size < 4 * 256 + 20 + 20) {
+ close(fd);
+ return error("index file %s is too small", path);
+ }
+ idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+
+ hdr = idx_map;
+ if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
+ version = ntohl(hdr->idx_version);
+ if (version < 2 || version > 2) {
+ munmap(idx_map, idx_size);
+ return error("index file %s is version %"PRIu32
+ " and is not supported by this binary"
+ " (try upgrading GIT to a newer version)",
+ path, version);
+ }
+ } else
+ version = 1;
+
+ nr = 0;
+ index = idx_map;
+ if (version > 1)
+ index += 2; /* skip index header */
+ for (i = 0; i < 256; i++) {
+ uint32_t n = ntohl(index[i]);
+ if (n < nr) {
+ munmap(idx_map, idx_size);
+ return error("non-monotonic index %s", path);
+ }
+ nr = n;
+ }
+
+ if (version == 1) {
+ /*
+ * Total size:
+ * - 256 index entries 4 bytes each
+ * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+ * - 20-byte SHA1 of the packfile
+ * - 20-byte SHA1 file checksum
+ */
+ if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+ munmap(idx_map, idx_size);
+ return error("wrong index v1 file size in %s", path);
+ }
+ } else if (version == 2) {
+ /*
+ * Minimum size:
+ * - 8 bytes of header
+ * - 256 index entries 4 bytes each
+ * - 20-byte sha1 entry * nr
+ * - 4-byte crc entry * nr
+ * - 4-byte offset entry * nr
+ * - 20-byte SHA1 of the packfile
+ * - 20-byte SHA1 file checksum
+ * And after the 4-byte offset table might be a
+ * variable sized table containing 8-byte entries
+ * for offsets larger than 2^31.
+ */
+ unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+ unsigned long max_size = min_size;
+ if (nr)
+ max_size += (nr - 1)*8;
+ if (idx_size < min_size || idx_size > max_size) {
+ munmap(idx_map, idx_size);
+ return error("wrong index v2 file size in %s", path);
+ }
+ if (idx_size != min_size &&
+ /*
+ * make sure we can deal with large pack offsets.
+ * 31-bit signed offset won't be enough, neither
+ * 32-bit unsigned one will be.
+ */
+ (sizeof(off_t) <= 4)) {
+ munmap(idx_map, idx_size);
+ return error("pack too large for current definition of off_t in %s", path);
+ }
+ }
+
+ p->index_version = version;
+ p->index_data = idx_map;
+ p->index_size = idx_size;
+ p->num_objects = nr;
+ return 0;
+}
+
+int open_pack_index(struct packed_git *p)
+{
+ char *idx_name;
+ int ret;
+
+ if (p->index_data)
+ return 0;
+
+ idx_name = xstrdup(p->pack_name);
+ strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
+ ret = check_packed_git_idx(idx_name, p);
+ free(idx_name);
+ return ret;
+}
+
+static void scan_windows(struct packed_git *p,
+ struct packed_git **lru_p,
+ struct pack_window **lru_w,
+ struct pack_window **lru_l)
+{
+ struct pack_window *w, *w_l;
+
+ for (w_l = NULL, w = p->windows; w; w = w->next) {
+ if (!w->inuse_cnt) {
+ if (!*lru_w || w->last_used < (*lru_w)->last_used) {
+ *lru_p = p;
+ *lru_w = w;
+ *lru_l = w_l;
+ }
+ }
+ w_l = w;
+ }
+}
+
+static int unuse_one_window(struct packed_git *current)
+{
+ struct packed_git *p, *lru_p = NULL;
+ struct pack_window *lru_w = NULL, *lru_l = NULL;
+
+ if (current)
+ scan_windows(current, &lru_p, &lru_w, &lru_l);
+ for (p = packed_git; p; p = p->next)
+ scan_windows(p, &lru_p, &lru_w, &lru_l);
+ if (lru_p) {
+ munmap(lru_w->base, lru_w->len);
+ pack_mapped -= lru_w->len;
+ if (lru_l)
+ lru_l->next = lru_w->next;
+ else
+ lru_p->windows = lru_w->next;
+ free(lru_w);
+ pack_open_windows--;
+ return 1;
+ }
+ return 0;
+}
+
+void release_pack_memory(size_t need)
+{
+ size_t cur = pack_mapped;
+ while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
+ ; /* nothing */
+}
+
+static void mmap_limit_check(size_t length)
+{
+ static size_t limit = 0;
+ if (!limit) {
+ limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
+ if (!limit)
+ limit = SIZE_MAX;
+ }
+ if (length > limit)
+ die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
+ (uintmax_t)length, (uintmax_t)limit);
+}
+
+void *xmmap_gently(void *start, size_t length,
+ int prot, int flags, int fd, off_t offset)
+{
+ void *ret;
+
+ mmap_limit_check(length);
+ ret = mmap(start, length, prot, flags, fd, offset);
+ if (ret == MAP_FAILED) {
+ if (!length)
+ return NULL;
+ release_pack_memory(length);
+ ret = mmap(start, length, prot, flags, fd, offset);
+ }
+ return ret;
+}
+
+void *xmmap(void *start, size_t length,
+ int prot, int flags, int fd, off_t offset)
+{
+ void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
+ if (ret == MAP_FAILED)
+ die_errno("mmap failed");
+ return ret;
+}
+
+void close_pack_windows(struct packed_git *p)
+{
+ while (p->windows) {
+ struct pack_window *w = p->windows;
+
+ if (w->inuse_cnt)
+ die("pack '%s' still has open windows to it",
+ p->pack_name);
+ munmap(w->base, w->len);
+ pack_mapped -= w->len;
+ pack_open_windows--;
+ p->windows = w->next;
+ free(w);
+ }
+}
+
+/*
+ * The LRU pack is the one with the oldest MRU window, preferring packs
+ * with no used windows, or the oldest mtime if it has no windows allocated.
+ */
+static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
+{
+ struct pack_window *w, *this_mru_w;
+ int has_windows_inuse = 0;
+
+ /*
+ * Reject this pack if it has windows and the previously selected
+ * one does not. If this pack does not have windows, reject
+ * it if the pack file is newer than the previously selected one.
+ */
+ if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
+ return;
+
+ for (w = this_mru_w = p->windows; w; w = w->next) {
+ /*
+ * Reject this pack if any of its windows are in use,
+ * but the previously selected pack did not have any
+ * inuse windows. Otherwise, record that this pack
+ * has windows in use.
+ */
+ if (w->inuse_cnt) {
+ if (*accept_windows_inuse)
+ has_windows_inuse = 1;
+ else
+ return;
+ }
+
+ if (w->last_used > this_mru_w->last_used)
+ this_mru_w = w;
+
+ /*
+ * Reject this pack if it has windows that have been
+ * used more recently than the previously selected pack.
+ * If the previously selected pack had windows inuse and
+ * we have not encountered a window in this pack that is
+ * inuse, skip this check since we prefer a pack with no
+ * inuse windows to one that has inuse windows.
+ */
+ if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
+ this_mru_w->last_used > (*mru_w)->last_used)
+ return;
+ }
+
+ /*
+ * Select this pack.
+ */
+ *mru_w = this_mru_w;
+ *lru_p = p;
+ *accept_windows_inuse = has_windows_inuse;
+}
+
+static int close_one_pack(void)
+{
+ struct packed_git *p, *lru_p = NULL;
+ struct pack_window *mru_w = NULL;
+ int accept_windows_inuse = 1;
+
+ for (p = packed_git; p; p = p->next) {
+ if (p->pack_fd == -1)
+ continue;
+ find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
+ }
+
+ if (lru_p) {
+ close(lru_p->pack_fd);
+ pack_open_fds--;
+ lru_p->pack_fd = -1;
+ return 1;
+ }
+
+ return 0;
+}
+
+void unuse_pack(struct pack_window **w_cursor)
+{
+ struct pack_window *w = *w_cursor;
+ if (w) {
+ w->inuse_cnt--;
+ *w_cursor = NULL;
+ }
+}
+
+void close_pack_index(struct packed_git *p)
+{
+ if (p->index_data) {
+ munmap((void *)p->index_data, p->index_size);
+ p->index_data = NULL;
+ }
+}
+
+/*
+ * This is used by git-repack in case a newly created pack happens to
+ * contain the same set of objects as an existing one. In that case
+ * the resulting file might be different even if its name would be the
+ * same. It is best to close any reference to the old pack before it is
+ * replaced on disk. Of course no index pointers or windows for given pack
+ * must subsist at this point. If ever objects from this pack are requested
+ * again, the new version of the pack will be reinitialized through
+ * reprepare_packed_git().
+ */
+void free_pack_by_name(const char *pack_name)
+{
+ struct packed_git *p, **pp = &packed_git;
+
+ while (*pp) {
+ p = *pp;
+ if (strcmp(pack_name, p->pack_name) == 0) {
+ clear_delta_base_cache();
+ close_pack_windows(p);
+ if (p->pack_fd != -1) {
+ close(p->pack_fd);
+ pack_open_fds--;
+ }
+ close_pack_index(p);
+ free(p->bad_object_sha1);
+ *pp = p->next;
+ if (last_found_pack == p)
+ last_found_pack = NULL;
+ free(p);
+ return;
+ }
+ pp = &p->next;
+ }
+}
+
+static unsigned int get_max_fd_limit(void)
+{
+#ifdef RLIMIT_NOFILE
+ {
+ struct rlimit lim;
+
+ if (!getrlimit(RLIMIT_NOFILE, &lim))
+ return lim.rlim_cur;
+ }
+#endif
+
+#ifdef _SC_OPEN_MAX
+ {
+ long open_max = sysconf(_SC_OPEN_MAX);
+ if (0 < open_max)
+ return open_max;
+ /*
+ * Otherwise, we got -1 for one of the two
+ * reasons:
+ *
+ * (1) sysconf() did not understand _SC_OPEN_MAX
+ * and signaled an error with -1; or
+ * (2) sysconf() said there is no limit.
+ *
+ * We _could_ clear errno before calling sysconf() to
+ * tell these two cases apart and return a huge number
+ * in the latter case to let the caller cap it to a
+ * value that is not so selfish, but letting the
+ * fallback OPEN_MAX codepath take care of these cases
+ * is a lot simpler.
+ */
+ }
+#endif
+
+#ifdef OPEN_MAX
+ return OPEN_MAX;
+#else
+ return 1; /* see the caller ;-) */
+#endif
+}
+
+/*
+ * Do not call this directly as this leaks p->pack_fd on error return;
+ * call open_packed_git() instead.
+ */
+static int open_packed_git_1(struct packed_git *p)
+{
+ struct stat st;
+ struct pack_header hdr;
+ unsigned char sha1[20];
+ unsigned char *idx_sha1;
+ long fd_flag;
+
+ if (!p->index_data && open_pack_index(p))
+ return error("packfile %s index unavailable", p->pack_name);
+
+ if (!pack_max_fds) {
+ unsigned int max_fds = get_max_fd_limit();
+
+ /* Save 3 for stdin/stdout/stderr, 22 for work */
+ if (25 < max_fds)
+ pack_max_fds = max_fds - 25;
+ else
+ pack_max_fds = 1;
+ }
+
+ while (pack_max_fds <= pack_open_fds && close_one_pack())
+ ; /* nothing */
+
+ p->pack_fd = git_open_noatime(p->pack_name);
+ if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
+ return -1;
+ pack_open_fds++;
+
+ /* If we created the struct before we had the pack we lack size. */
+ if (!p->pack_size) {
+ if (!S_ISREG(st.st_mode))
+ return error("packfile %s not a regular file", p->pack_name);
+ p->pack_size = st.st_size;
+ } else if (p->pack_size != st.st_size)
+ return error("packfile %s size changed", p->pack_name);
+
+ /* We leave these file descriptors open with sliding mmap;
+ * there is no point keeping them open across exec(), though.
+ */
+ fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
+ if (fd_flag < 0)
+ return error("cannot determine file descriptor flags");
+ fd_flag |= FD_CLOEXEC;
+ if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
+ return error("cannot set FD_CLOEXEC");
+
+ /* Verify we recognize this pack file format. */
+ if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+ return error("file %s is far too short to be a packfile", p->pack_name);
+ if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
+ return error("file %s is not a GIT packfile", p->pack_name);
+ if (!pack_version_ok(hdr.hdr_version))
+ return error("packfile %s is version %"PRIu32" and not"
+ " supported (try upgrading GIT to a newer version)",
+ p->pack_name, ntohl(hdr.hdr_version));
+
+ /* Verify the pack matches its index. */
+ if (p->num_objects != ntohl(hdr.hdr_entries))
+ return error("packfile %s claims to have %"PRIu32" objects"
+ " while index indicates %"PRIu32" objects",
+ p->pack_name, ntohl(hdr.hdr_entries),
+ p->num_objects);
+ if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
+ return error("end of packfile %s is unavailable", p->pack_name);
+ if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
+ return error("packfile %s signature is unavailable", p->pack_name);
+ idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
+ if (hashcmp(sha1, idx_sha1))
+ return error("packfile %s does not match index", p->pack_name);
+ return 0;
+}
+
+static int open_packed_git(struct packed_git *p)
+{
+ if (!open_packed_git_1(p))
+ return 0;
+ if (p->pack_fd != -1) {
+ close(p->pack_fd);
+ pack_open_fds--;
+ p->pack_fd = -1;
+ }
+ return -1;
+}
+
+static int in_window(struct pack_window *win, off_t offset)
+{
+ /* We must promise at least 20 bytes (one hash) after the
+ * offset is available from this window, otherwise the offset
+ * is not actually in this window and a different window (which
+ * has that one hash excess) must be used. This is to support
+ * the object header and delta base parsing routines below.
+ */
+ off_t win_off = win->offset;
+ return win_off <= offset
+ && (offset + 20) <= (win_off + win->len);
+}
+
+unsigned char *use_pack(struct packed_git *p,
+ struct pack_window **w_cursor,
+ off_t offset,
+ unsigned long *left)
+{
+ struct pack_window *win = *w_cursor;
+
+ /* Since packfiles end in a hash of their content and it's
+ * pointless to ask for an offset into the middle of that
+ * hash, and the in_window function above wouldn't match
+ * don't allow an offset too close to the end of the file.
+ */
+ if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
+ die("packfile %s cannot be accessed", p->pack_name);
+ if (offset > (p->pack_size - 20))
+ die("offset beyond end of packfile (truncated pack?)");
+
+ if (!win || !in_window(win, offset)) {
+ if (win)
+ win->inuse_cnt--;
+ for (win = p->windows; win; win = win->next) {
+ if (in_window(win, offset))
+ break;
+ }
+ if (!win) {
+ size_t window_align = packed_git_window_size / 2;
+ off_t len;
+
+ if (p->pack_fd == -1 && open_packed_git(p))
+ die("packfile %s cannot be accessed", p->pack_name);
+
+ win = xcalloc(1, sizeof(*win));
+ win->offset = (offset / window_align) * window_align;
+ len = p->pack_size - win->offset;
+ if (len > packed_git_window_size)
+ len = packed_git_window_size;
+ win->len = (size_t)len;
+ pack_mapped += win->len;
+ while (packed_git_limit < pack_mapped
+ && unuse_one_window(p))
+ ; /* nothing */
+ win->base = xmmap(NULL, win->len,
+ PROT_READ, MAP_PRIVATE,
+ p->pack_fd, win->offset);
+ if (win->base == MAP_FAILED)
+ die("packfile %s cannot be mapped: %s",
+ p->pack_name,
+ strerror(errno));
+ if (!win->offset && win->len == p->pack_size
+ && !p->do_not_close) {
+ close(p->pack_fd);
+ pack_open_fds--;
+ p->pack_fd = -1;
+ }
+ pack_mmap_calls++;
+ pack_open_windows++;
+ if (pack_mapped > peak_pack_mapped)
+ peak_pack_mapped = pack_mapped;
+ if (pack_open_windows > peak_pack_open_windows)
+ peak_pack_open_windows = pack_open_windows;
+ win->next = p->windows;
+ p->windows = win;
+ }
+ }
+ if (win != *w_cursor) {
+ win->last_used = pack_used_ctr++;
+ win->inuse_cnt++;
+ *w_cursor = win;
+ }
+ offset -= win->offset;
+ if (left)
+ *left = win->len - xsize_t(offset);
+ return win->base + offset;
+}
+
+static struct packed_git *alloc_packed_git(int extra)
+{
+ struct packed_git *p = xmalloc(sizeof(*p) + extra);
+ memset(p, 0, sizeof(*p));
+ p->pack_fd = -1;
+ return p;
+}
+
+static void try_to_free_pack_memory(size_t size)
+{
+ release_pack_memory(size);
+}
+
+struct packed_git *add_packed_git(const char *path, int path_len, int local)
+{
+ static int have_set_try_to_free_routine;
+ struct stat st;
+ struct packed_git *p = alloc_packed_git(path_len + 2);
+
+ if (!have_set_try_to_free_routine) {
+ have_set_try_to_free_routine = 1;
+ set_try_to_free_routine(try_to_free_pack_memory);
+ }
+
+ /*
+ * Make sure a corresponding .pack file exists and that
+ * the index looks sane.
+ */
+ path_len -= strlen(".idx");
+ if (path_len < 1) {
+ free(p);
+ return NULL;
+ }
+ memcpy(p->pack_name, path, path_len);
+
+ strcpy(p->pack_name + path_len, ".keep");
+ if (!access(p->pack_name, F_OK))
+ p->pack_keep = 1;
+
+ strcpy(p->pack_name + path_len, ".pack");
+ if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
+ free(p);
+ return NULL;
+ }
+
+ /* ok, it looks sane as far as we can check without
+ * actually mapping the pack file.
+ */
+ p->pack_size = st.st_size;
+ p->pack_local = local;
+ p->mtime = st.st_mtime;
+ if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
+ hashclr(p->sha1);
+ return p;
+}
+
+struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
+{
+ const char *path = sha1_pack_name(sha1);
+ struct packed_git *p = alloc_packed_git(strlen(path) + 1);
+
+ strcpy(p->pack_name, path);
+ hashcpy(p->sha1, sha1);
+ if (check_packed_git_idx(idx_path, p)) {
+ free(p);
+ return NULL;
+ }
+
+ return p;
+}
+
+void install_packed_git(struct packed_git *pack)
+{
+ if (pack->pack_fd != -1)
+ pack_open_fds++;
+
+ pack->next = packed_git;
+ packed_git = pack;
+}
+
+void (*report_garbage)(const char *desc, const char *path);
+
+static void report_helper(const struct string_list *list,
+ int seen_bits, int first, int last)
+{
+ const char *msg;
+ switch (seen_bits) {
+ case 0:
+ msg = "no corresponding .idx or .pack";
+ break;
+ case 1:
+ msg = "no corresponding .idx";
+ break;
+ case 2:
+ msg = "no corresponding .pack";
+ break;
+ default:
+ return;
+ }
+ for (; first < last; first++)
+ report_garbage(msg, list->items[first].string);
+}
+
+static void report_pack_garbage(struct string_list *list)
+{
+ int i, baselen = -1, first = 0, seen_bits = 0;
+
+ if (!report_garbage)
+ return;
+
+ string_list_sort(list);
+
+ for (i = 0; i < list->nr; i++) {
+ const char *path = list->items[i].string;
+ if (baselen != -1 &&
+ strncmp(path, list->items[first].string, baselen)) {
+ report_helper(list, seen_bits, first, i);
+ baselen = -1;
+ seen_bits = 0;
+ }
+ if (baselen == -1) {
+ const char *dot = strrchr(path, '.');
+ if (!dot) {
+ report_garbage("garbage found", path);
+ continue;
+ }
+ baselen = dot - path + 1;
+ first = i;
+ }
+ if (!strcmp(path + baselen, "pack"))
+ seen_bits |= 1;
+ else if (!strcmp(path + baselen, "idx"))
+ seen_bits |= 2;
+ }
+ report_helper(list, seen_bits, first, list->nr);
+}
+
+static void prepare_packed_git_one(char *objdir, int local)
+{
+ struct strbuf path = STRBUF_INIT;
+ size_t dirnamelen;
+ DIR *dir;
+ struct dirent *de;
+ struct string_list garbage = STRING_LIST_INIT_DUP;
+
+ strbuf_addstr(&path, objdir);
+ strbuf_addstr(&path, "/pack");
+ dir = opendir(path.buf);
+ if (!dir) {
+ if (errno != ENOENT)
+ error("unable to open object pack directory: %s: %s",
+ path.buf, strerror(errno));
+ strbuf_release(&path);
+ return;
+ }
+ strbuf_addch(&path, '/');
+ dirnamelen = path.len;
+ while ((de = readdir(dir)) != NULL) {
+ struct packed_git *p;
+ size_t base_len;
+
+ if (is_dot_or_dotdot(de->d_name))
+ continue;
+
+ strbuf_setlen(&path, dirnamelen);
+ strbuf_addstr(&path, de->d_name);
+
+ base_len = path.len;
+ if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
+ /* Don't reopen a pack we already have. */
+ for (p = packed_git; p; p = p->next) {
+ size_t len;
+ if (strip_suffix(p->pack_name, ".pack", &len) &&
+ len == base_len &&
+ !memcmp(p->pack_name, path.buf, len))
+ break;
+ }
+ if (p == NULL &&
+ /*
+ * See if it really is a valid .idx file with
+ * corresponding .pack file that we can map.
+ */
+ (p = add_packed_git(path.buf, path.len, local)) != NULL)
+ install_packed_git(p);
+ }
+
+ if (!report_garbage)
+ continue;
+
+ if (ends_with(de->d_name, ".idx") ||
+ ends_with(de->d_name, ".pack") ||
+ ends_with(de->d_name, ".bitmap") ||
+ ends_with(de->d_name, ".keep"))
+ string_list_append(&garbage, path.buf);
+ else
+ report_garbage("garbage found", path.buf);
+ }
+ closedir(dir);
+ report_pack_garbage(&garbage);
+ string_list_clear(&garbage, 0);
+ strbuf_release(&path);
+}
+
+static int sort_pack(const void *a_, const void *b_)
+{
+ struct packed_git *a = *((struct packed_git **)a_);
+ struct packed_git *b = *((struct packed_git **)b_);
+ int st;
+
+ /*
+ * Local packs tend to contain objects specific to our
+ * variant of the project than remote ones. In addition,
+ * remote ones could be on a network mounted filesystem.
+ * Favor local ones for these reasons.
+ */
+ st = a->pack_local - b->pack_local;
+ if (st)
+ return -st;
+
+ /*
+ * Younger packs tend to contain more recent objects,
+ * and more recent objects tend to get accessed more
+ * often.
+ */
+ if (a->mtime < b->mtime)
+ return 1;
+ else if (a->mtime == b->mtime)
+ return 0;
+ return -1;
+}
+
+static void rearrange_packed_git(void)
+{
+ struct packed_git **ary, *p;
+ int i, n;
+
+ for (n = 0, p = packed_git; p; p = p->next)
+ n++;
+ if (n < 2)
+ return;
+
+ /* prepare an array of packed_git for easier sorting */
+ ary = xcalloc(n, sizeof(struct packed_git *));
+ for (n = 0, p = packed_git; p; p = p->next)
+ ary[n++] = p;
+
+ qsort(ary, n, sizeof(struct packed_git *), sort_pack);
+
+ /* link them back again */
+ for (i = 0; i < n - 1; i++)
+ ary[i]->next = ary[i + 1];
+ ary[n - 1]->next = NULL;
+ packed_git = ary[0];
+
+ free(ary);
+}
+
+static int prepare_packed_git_run_once = 0;
+void prepare_packed_git(void)
+{
+ struct alternate_object_database *alt;
+
+ if (prepare_packed_git_run_once)
+ return;
+ prepare_packed_git_one(get_object_directory(), 1);
+ prepare_alt_odb();
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ alt->name[-1] = 0;
+ prepare_packed_git_one(alt->base, 0);
+ alt->name[-1] = '/';
+ }
+ rearrange_packed_git();
+ prepare_packed_git_run_once = 1;
+}
+
+void reprepare_packed_git(void)
+{
+ prepare_packed_git_run_once = 0;
+ prepare_packed_git();
+}
+
+static void mark_bad_packed_object(struct packed_git *p,
+ const unsigned char *sha1)
+{
+ unsigned i;
+ for (i = 0; i < p->num_bad_objects; i++)
+ if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+ return;
+ p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
+ hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
+ p->num_bad_objects++;
+}
+
+static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
+{
+ struct packed_git *p;
+ unsigned i;
+
+ for (p = packed_git; p; p = p->next)
+ for (i = 0; i < p->num_bad_objects; i++)
+ if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+ return p;
+ return NULL;
+}
+
+/*
+ * With an in-core object data in "map", rehash it to make sure the
+ * object name actually matches "sha1" to detect object corruption.
+ * With "map" == NULL, try reading the object named with "sha1" using
+ * the streaming interface and rehash it to do the same.
+ */
+int check_sha1_signature(const unsigned char *sha1, void *map,
+ unsigned long size, const char *type)
+{
+ unsigned char real_sha1[20];
+ enum object_type obj_type;
+ struct git_istream *st;
+ git_SHA_CTX c;
+ char hdr[32];
+ int hdrlen;
+
+ if (map) {
+ hash_sha1_file(map, size, type, real_sha1);
+ return hashcmp(sha1, real_sha1) ? -1 : 0;
+ }
+
+ st = open_istream(sha1, &obj_type, &size, NULL);
+ if (!st)
+ return -1;
+
+ /* Generate the header */
+ hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
+
+ /* Sha1.. */
+ git_SHA1_Init(&c);
+ git_SHA1_Update(&c, hdr, hdrlen);
+ for (;;) {
+ char buf[1024 * 16];
+ ssize_t readlen = read_istream(st, buf, sizeof(buf));
+
+ if (readlen < 0) {
+ close_istream(st);
+ return -1;
+ }
+ if (!readlen)
+ break;
+ git_SHA1_Update(&c, buf, readlen);
+ }
+ git_SHA1_Final(real_sha1, &c);
+ close_istream(st);
+ return hashcmp(sha1, real_sha1) ? -1 : 0;
+}
+
+int git_open_noatime(const char *name)
+{
+ static int sha1_file_open_flag = O_NOATIME;
+
+ for (;;) {
+ int fd;
+
+ errno = 0;
+ fd = open(name, O_RDONLY | sha1_file_open_flag);
+ if (fd >= 0)
+ return fd;
+
+ /* Might the failure be due to O_NOATIME? */
+ if (errno != ENOENT && sha1_file_open_flag) {
+ sha1_file_open_flag = 0;
+ continue;
+ }
+
+ return -1;
+ }
+}
+
+static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
+{
+ struct alternate_object_database *alt;
+
+ if (!lstat(sha1_file_name(sha1), st))
+ return 0;
+
+ prepare_alt_odb();
+ errno = ENOENT;
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ fill_sha1_path(alt->name, sha1);
+ if (!lstat(alt->base, st))
+ return 0;
+ }
+
+ return -1;
+}
+
+static int open_sha1_file(const unsigned char *sha1)
+{
+ int fd;
+ struct alternate_object_database *alt;
+ int most_interesting_errno;
+
+ fd = git_open_noatime(sha1_file_name(sha1));
+ if (fd >= 0)
+ return fd;
+ most_interesting_errno = errno;
+
+ prepare_alt_odb();
+ for (alt = alt_odb_list; alt; alt = alt->next) {
+ fill_sha1_path(alt->name, sha1);
+ fd = git_open_noatime(alt->base);
+ if (fd >= 0)
+ return fd;
+ if (most_interesting_errno == ENOENT)
+ most_interesting_errno = errno;
+ }
+ errno = most_interesting_errno;
+ return -1;
+}
+
+void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+{
+ void *map;
+ int fd;
+
+ fd = open_sha1_file(sha1);
+ map = NULL;
+ if (fd >= 0) {
+ struct stat st;
+
+ if (!fstat(fd, &st)) {
+ *size = xsize_t(st.st_size);
+ if (!*size) {
+ /* mmap() is forbidden on empty files */
+ error("object file %s is empty", sha1_file_name(sha1));
+ return NULL;
+ }
+ map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
+ }
+ close(fd);
+ }
+ return map;
+}
+
+unsigned long unpack_object_header_buffer(const unsigned char *buf,
+ unsigned long len, enum object_type *type, unsigned long *sizep)
+{
+ unsigned shift;
+ unsigned long size, c;
+ unsigned long used = 0;
+
+ c = buf[used++];
+ *type = (c >> 4) & 7;
+ size = c & 15;
+ shift = 4;
+ while (c & 0x80) {
+ if (len <= used || bitsizeof(long) <= shift) {
+ error("bad object header");
+ size = used = 0;
+ break;
+ }
+ c = buf[used++];
+ size += (c & 0x7f) << shift;
+ shift += 7;
+ }
+ *sizep = size;
+ return used;
+}
+
+int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
+{
+ /* Get the data stream */
+ memset(stream, 0, sizeof(*stream));
+ stream->next_in = map;
+ stream->avail_in = mapsize;
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+
+ git_inflate_init(stream);
+ return git_inflate(stream, 0);
+}
+
+static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
+ unsigned long mapsize, void *buffer,
+ unsigned long bufsiz, struct strbuf *header)
+{
+ int status;
+
+ status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
+
+ /*
+ * Check if entire header is unpacked in the first iteration.
+ */
+ if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+ return 0;
+
+ /*
+ * buffer[0..bufsiz] was not large enough. Copy the partial
+ * result out to header, and then append the result of further
+ * reading the stream.
+ */
+ strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+
+ do {
+ status = git_inflate(stream, 0);
+ strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+ if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+ return 0;
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+ } while (status != Z_STREAM_END);
+ return -1;
+}
+
+static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
+{
+ int bytes = strlen(buffer) + 1;
+ unsigned char *buf = xmallocz(size);
+ unsigned long n;
+ int status = Z_OK;
+
+ n = stream->total_out - bytes;
+ if (n > size)
+ n = size;
+ memcpy(buf, (char *) buffer + bytes, n);
+ bytes = n;
+ if (bytes <= size) {
+ /*
+ * The above condition must be (bytes <= size), not
+ * (bytes < size). In other words, even though we
+ * expect no more output and set avail_out to zero,
+ * the input zlib stream may have bytes that express
+ * "this concludes the stream", and we *do* want to
+ * eat that input.
+ *
+ * Otherwise we would not be able to test that we
+ * consumed all the input to reach the expected size;
+ * we also want to check that zlib tells us that all
+ * went well with status == Z_STREAM_END at the end.
+ */
+ stream->next_out = buf + bytes;
+ stream->avail_out = size - bytes;
+ while (status == Z_OK)
+ status = git_inflate(stream, Z_FINISH);
+ }
+ if (status == Z_STREAM_END && !stream->avail_in) {
+ git_inflate_end(stream);
+ return buf;
+ }
+
+ if (status < 0)
+ error("corrupt loose object '%s'", sha1_to_hex(sha1));
+ else if (stream->avail_in)
+ error("garbage at end of loose object '%s'",
+ sha1_to_hex(sha1));
+ free(buf);
+ return NULL;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * too permissive for what we want to check. So do an anal
+ * object header parse by hand.
+ */
+static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
+ unsigned int flags)
+{
+ const char *type_buf = hdr;
+ unsigned long size;
+ int type, type_len = 0;
+
+ /*
+ * The type can be of any size but is followed by
+ * a space.
+ */
+ for (;;) {
+ char c = *hdr++;
+ if (c == ' ')
+ break;
+ type_len++;
+ }
+
+ type = type_from_string_gently(type_buf, type_len, 1);
+ if (oi->typename)
+ strbuf_add(oi->typename, type_buf, type_len);
+ /*
+ * Set type to 0 if its an unknown object and
+ * we're obtaining the type using '--allow-unkown-type'
+ * option.
+ */
+ if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
+ type = 0;
+ else if (type < 0)
+ die("invalid object type");
+ if (oi->typep)
+ *oi->typep = type;
+
+ /*
+ * The length must follow immediately, and be in canonical
+ * decimal format (ie "010" is not valid).
+ */
+ size = *hdr++ - '0';
+ if (size > 9)
+ return -1;
+ if (size) {
+ for (;;) {
+ unsigned long c = *hdr - '0';
+ if (c > 9)
+ break;
+ hdr++;
+ size = size * 10 + c;
+ }
+ }
+
+ if (oi->sizep)
+ *oi->sizep = size;
+
+ /*
+ * The length must be followed by a zero byte
+ */
+ return *hdr ? -1 : type;
+}
+
+int parse_sha1_header(const char *hdr, unsigned long *sizep)
+{
+ struct object_info oi;
+
+ oi.sizep = sizep;
+ oi.typename = NULL;
+ oi.typep = NULL;
+ return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
+}
+
+static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
+{
+ int ret;
+ git_zstream stream;
+ char hdr[8192];
+
+ ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
+ if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
+ return NULL;
+
+ return unpack_sha1_rest(&stream, hdr, *size, sha1);
+}
+
+unsigned long get_size_from_delta(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos)
+{
+ const unsigned char *data;
+ unsigned char delta_head[20], *in;
+ git_zstream stream;
+ int st;
+
+ memset(&stream, 0, sizeof(stream));
+ stream.next_out = delta_head;
+ stream.avail_out = sizeof(delta_head);
+
+ git_inflate_init(&stream);
+ do {
+ in = use_pack(p, w_curs, curpos, &stream.avail_in);
+ stream.next_in = in;
+ st = git_inflate(&stream, Z_FINISH);
+ curpos += stream.next_in - in;
+ } while ((st == Z_OK || st == Z_BUF_ERROR) &&
+ stream.total_out < sizeof(delta_head));
+ git_inflate_end(&stream);
+ if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
+ error("delta data unpack-initial failed");
+ return 0;
+ }
+
+ /* Examine the initial part of the delta to figure out
+ * the result size.
+ */
+ data = delta_head;
+
+ /* ignore base size */
+ get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+
+ /* Read the result size */
+ return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
+}
+
+static off_t get_delta_base(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t *curpos,
+ enum object_type type,
+ off_t delta_obj_offset)
+{
+ unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
+ off_t base_offset;
+
+ /* use_pack() assured us we have [base_info, base_info + 20)
+ * as a range that we can look at without walking off the
+ * end of the mapped window. Its actually the hash size
+ * that is assured. An OFS_DELTA longer than the hash size
+ * is stupid, as then a REF_DELTA would be smaller to store.
+ */
+ if (type == OBJ_OFS_DELTA) {
+ unsigned used = 0;
+ unsigned char c = base_info[used++];
+ base_offset = c & 127;
+ while (c & 128) {
+ base_offset += 1;
+ if (!base_offset || MSB(base_offset, 7))
+ return 0; /* overflow */
+ c = base_info[used++];
+ base_offset = (base_offset << 7) + (c & 127);
+ }
+ base_offset = delta_obj_offset - base_offset;
+ if (base_offset <= 0 || base_offset >= delta_obj_offset)
+ return 0; /* out of bound */
+ *curpos += used;
+ } else if (type == OBJ_REF_DELTA) {
+ /* The base entry _must_ be in the same pack */
+ base_offset = find_pack_entry_one(base_info, p);
+ *curpos += 20;
+ } else
+ die("I am totally screwed");
+ return base_offset;
+}
+
+/*
+ * Like get_delta_base above, but we return the sha1 instead of the pack
+ * offset. This means it is cheaper for REF deltas (we do not have to do
+ * the final object lookup), but more expensive for OFS deltas (we
+ * have to load the revidx to convert the offset back into a sha1).
+ */
+static const unsigned char *get_delta_base_sha1(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos,
+ enum object_type type,
+ off_t delta_obj_offset)
+{
+ if (type == OBJ_REF_DELTA) {
+ unsigned char *base = use_pack(p, w_curs, curpos, NULL);
+ return base;
+ } else if (type == OBJ_OFS_DELTA) {
+ struct revindex_entry *revidx;
+ off_t base_offset = get_delta_base(p, w_curs, &curpos,
+ type, delta_obj_offset);
+
+ if (!base_offset)
+ return NULL;
+
+ revidx = find_pack_revindex(p, base_offset);
+ if (!revidx)
+ return NULL;
+
+ return nth_packed_object_sha1(p, revidx->nr);
+ } else
+ return NULL;
+}
+
+int unpack_object_header(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t *curpos,
+ unsigned long *sizep)
+{
+ unsigned char *base;
+ unsigned long left;
+ unsigned long used;
+ enum object_type type;
+
+ /* use_pack() assures us we have [base, base + 20) available
+ * as a range that we can look at. (Its actually the hash
+ * size that is assured.) With our object header encoding
+ * the maximum deflated object size is 2^137, which is just
+ * insane, so we know won't exceed what we have been given.
+ */
+ base = use_pack(p, w_curs, *curpos, &left);
+ used = unpack_object_header_buffer(base, left, &type, sizep);
+ if (!used) {
+ type = OBJ_BAD;
+ } else
+ *curpos += used;
+
+ return type;
+}
+
+static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
+{
+ int type;
+ struct revindex_entry *revidx;
+ const unsigned char *sha1;
+ revidx = find_pack_revindex(p, obj_offset);
+ if (!revidx)
+ return OBJ_BAD;
+ sha1 = nth_packed_object_sha1(p, revidx->nr);
+ mark_bad_packed_object(p, sha1);
+ type = sha1_object_info(sha1, NULL);
+ if (type <= OBJ_NONE)
+ return OBJ_BAD;
+ return type;
+}
+
+#define POI_STACK_PREALLOC 64
+
+static enum object_type packed_to_object_type(struct packed_git *p,
+ off_t obj_offset,
+ enum object_type type,
+ struct pack_window **w_curs,
+ off_t curpos)
+{
+ off_t small_poi_stack[POI_STACK_PREALLOC];
+ off_t *poi_stack = small_poi_stack;
+ int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
+
+ while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ off_t base_offset;
+ unsigned long size;
+ /* Push the object we're going to leave behind */
+ if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
+ poi_stack_alloc = alloc_nr(poi_stack_nr);
+ poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
+ memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
+ } else {
+ ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
+ }
+ poi_stack[poi_stack_nr++] = obj_offset;
+ /* If parsing the base offset fails, just unwind */
+ base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
+ if (!base_offset)
+ goto unwind;
+ curpos = obj_offset = base_offset;
+ type = unpack_object_header(p, w_curs, &curpos, &size);
+ if (type <= OBJ_NONE) {
+ /* If getting the base itself fails, we first
+ * retry the base, otherwise unwind */
+ type = retry_bad_packed_offset(p, base_offset);
+ if (type > OBJ_NONE)
+ goto out;
+ goto unwind;
+ }
+ }
+
+ switch (type) {
+ case OBJ_BAD:
+ case OBJ_COMMIT:
+ case OBJ_TREE:
+ case OBJ_BLOB:
+ case OBJ_TAG:
+ break;
+ default:
+ error("unknown object type %i at offset %"PRIuMAX" in %s",
+ type, (uintmax_t)obj_offset, p->pack_name);
+ type = OBJ_BAD;
+ }
+
+out:
+ if (poi_stack != small_poi_stack)
+ free(poi_stack);
+ return type;
+
+unwind:
+ while (poi_stack_nr) {
+ obj_offset = poi_stack[--poi_stack_nr];
+ type = retry_bad_packed_offset(p, obj_offset);
+ if (type > OBJ_NONE)
+ goto out;
+ }
+ type = OBJ_BAD;
+ goto out;
+}
+
+static int packed_object_info(struct packed_git *p, off_t obj_offset,
+ struct object_info *oi)
+{
+ struct pack_window *w_curs = NULL;
+ unsigned long size;
+ off_t curpos = obj_offset;
+ enum object_type type;
+
+ /*
+ * We always get the representation type, but only convert it to
+ * a "real" type later if the caller is interested.
+ */
+ type = unpack_object_header(p, &w_curs, &curpos, &size);
+
+ if (oi->sizep) {
+ if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ off_t tmp_pos = curpos;
+ off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
+ type, obj_offset);
+ if (!base_offset) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
+ if (*oi->sizep == 0) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ } else {
+ *oi->sizep = size;
+ }
+ }
+
+ if (oi->disk_sizep) {
+ struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+ *oi->disk_sizep = revidx[1].offset - obj_offset;
+ }
+
+ if (oi->typep) {
+ *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
+ if (*oi->typep < 0) {
+ type = OBJ_BAD;
+ goto out;
+ }
+ }
+
+ if (oi->delta_base_sha1) {
+ if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
+ const unsigned char *base;
+
+ base = get_delta_base_sha1(p, &w_curs, curpos,
+ type, obj_offset);
+ if (!base) {
+ type = OBJ_BAD;
+ goto out;
+ }
+
+ hashcpy(oi->delta_base_sha1, base);
+ } else
+ hashclr(oi->delta_base_sha1);
+ }
+
+out:
+ unuse_pack(&w_curs);
+ return type;
+}
+
+static void *unpack_compressed_entry(struct packed_git *p,
+ struct pack_window **w_curs,
+ off_t curpos,
+ unsigned long size)
+{
+ int st;
+ git_zstream stream;
+ unsigned char *buffer, *in;
+
+ buffer = xmallocz_gently(size);
+ if (!buffer)
+ return NULL;
+ memset(&stream, 0, sizeof(stream));
+ stream.next_out = buffer;
+ stream.avail_out = size + 1;
+
+ git_inflate_init(&stream);
+ do {
+ in = use_pack(p, w_curs, curpos, &stream.avail_in);
+ stream.next_in = in;
+ st = git_inflate(&stream, Z_FINISH);
+ if (!stream.avail_out)
+ break; /* the payload is larger than it should be */
+ curpos += stream.next_in - in;
+ } while (st == Z_OK || st == Z_BUF_ERROR);
+ git_inflate_end(&stream);
+ if ((st != Z_STREAM_END) || stream.total_out != size) {
+ free(buffer);
+ return NULL;
+ }
+
+ return buffer;
+}
+
+#define MAX_DELTA_CACHE (256)
+
+static size_t delta_base_cached;
+
+static struct delta_base_cache_lru_list {
+ struct delta_base_cache_lru_list *prev;
+ struct delta_base_cache_lru_list *next;
+} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
+
+static struct delta_base_cache_entry {
+ struct delta_base_cache_lru_list lru;
+ void *data;
+ struct packed_git *p;
+ off_t base_offset;
+ unsigned long size;
+ enum object_type type;
+} delta_base_cache[MAX_DELTA_CACHE];
+
+static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
+{
+ unsigned long hash;
+
+ hash = (unsigned long)p + (unsigned long)base_offset;
+ hash += (hash >> 8) + (hash >> 16);
+ return hash % MAX_DELTA_CACHE;
+}
+
+static struct delta_base_cache_entry *
+get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
+{
+ unsigned long hash = pack_entry_hash(p, base_offset);
+ return delta_base_cache + hash;
+}
+
+static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
+ struct packed_git *p, off_t base_offset)
+{
+ return (ent->data && ent->p == p && ent->base_offset == base_offset);
+}
+
+static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
+{
+ struct delta_base_cache_entry *ent;
+ ent = get_delta_base_cache_entry(p, base_offset);
+ return eq_delta_base_cache_entry(ent, p, base_offset);
+}
+
+static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
+{
+ ent->data = NULL;
+ ent->lru.next->prev = ent->lru.prev;
+ ent->lru.prev->next = ent->lru.next;
+ delta_base_cached -= ent->size;
+}
+
+static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
+ unsigned long *base_size, enum object_type *type, int keep_cache)
+{
+ struct delta_base_cache_entry *ent;
+ void *ret;
+
+ ent = get_delta_base_cache_entry(p, base_offset);
+
+ if (!eq_delta_base_cache_entry(ent, p, base_offset))
+ return unpack_entry(p, base_offset, type, base_size);
+
+ ret = ent->data;
+
+ if (!keep_cache)
+ clear_delta_base_cache_entry(ent);
+ else
+ ret = xmemdupz(ent->data, ent->size);
+ *type = ent->type;
+ *base_size = ent->size;
+ return ret;
+}
+
+static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
+{
+ if (ent->data) {
+ free(ent->data);
+ ent->data = NULL;
+ ent->lru.next->prev = ent->lru.prev;
+ ent->lru.prev->next = ent->lru.next;
+ delta_base_cached -= ent->size;
+ }
+}
+
+void clear_delta_base_cache(void)
+{
+ unsigned long p;
+ for (p = 0; p < MAX_DELTA_CACHE; p++)
+ release_delta_base_cache(&delta_base_cache[p]);
+}
+
+static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
+ void *base, unsigned long base_size, enum object_type type)
+{
+ unsigned long hash = pack_entry_hash(p, base_offset);
+ struct delta_base_cache_entry *ent = delta_base_cache + hash;
+ struct delta_base_cache_lru_list *lru;
+
+ release_delta_base_cache(ent);
+ delta_base_cached += base_size;
+
+ for (lru = delta_base_cache_lru.next;
+ delta_base_cached > delta_base_cache_limit
+ && lru != &delta_base_cache_lru;
+ lru = lru->next) {
+ struct delta_base_cache_entry *f = (void *)lru;
+ if (f->type == OBJ_BLOB)
+ release_delta_base_cache(f);
+ }
+ for (lru = delta_base_cache_lru.next;
+ delta_base_cached > delta_base_cache_limit
+ && lru != &delta_base_cache_lru;
+ lru = lru->next) {
+ struct delta_base_cache_entry *f = (void *)lru;
+ release_delta_base_cache(f);
+ }
+
+ ent->p = p;
+ ent->base_offset = base_offset;
+ ent->type = type;
+ ent->data = base;
+ ent->size = base_size;
+ ent->lru.next = &delta_base_cache_lru;
+ ent->lru.prev = delta_base_cache_lru.prev;
+ delta_base_cache_lru.prev->next = &ent->lru;
+ delta_base_cache_lru.prev = &ent->lru;
+}
+
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+ unsigned long *size);
+
+static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
+{
+ static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
+ trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
+ p->pack_name, (uintmax_t)obj_offset);
+}
+
+int do_check_packed_object_crc;
+
+#define UNPACK_ENTRY_STACK_PREALLOC 64
+struct unpack_entry_stack_ent {
+ off_t obj_offset;
+ off_t curpos;
+ unsigned long size;
+};
+
+void *unpack_entry(struct packed_git *p, off_t obj_offset,
+ enum object_type *final_type, unsigned long *final_size)
+{
+ struct pack_window *w_curs = NULL;
+ off_t curpos = obj_offset;
+ void *data = NULL;
+ unsigned long size;
+ enum object_type type;
+ struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
+ struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
+ int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
+ int base_from_cache = 0;
+
+ write_pack_access_log(p, obj_offset);
+
+ /* PHASE 1: drill down to the innermost base object */
+ for (;;) {
+ off_t base_offset;
+ int i;
+ struct delta_base_cache_entry *ent;
+
+ ent = get_delta_base_cache_entry(p, curpos);
+ if (eq_delta_base_cache_entry(ent, p, curpos)) {
+ type = ent->type;
+ data = ent->data;
+ size = ent->size;
+ clear_delta_base_cache_entry(ent);
+ base_from_cache = 1;
+ break;
+ }
+
+ if (do_check_packed_object_crc && p->index_version > 1) {
+ struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
+ unsigned long len = revidx[1].offset - obj_offset;
+ if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
+ const unsigned char *sha1 =
+ nth_packed_object_sha1(p, revidx->nr);
+ error("bad packed object CRC for %s",
+ sha1_to_hex(sha1));
+ mark_bad_packed_object(p, sha1);
+ unuse_pack(&w_curs);
+ return NULL;
+ }
+ }
+
+ type = unpack_object_header(p, &w_curs, &curpos, &size);
+ if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
+ break;
+
+ base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
+ if (!base_offset) {
+ error("failed to validate delta base reference "
+ "at offset %"PRIuMAX" from %s",
+ (uintmax_t)curpos, p->pack_name);
+ /* bail to phase 2, in hopes of recovery */
+ data = NULL;
+ break;
+ }
+
+ /* push object, proceed to base */
+ if (delta_stack_nr >= delta_stack_alloc
+ && delta_stack == small_delta_stack) {
+ delta_stack_alloc = alloc_nr(delta_stack_nr);
+ delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
+ memcpy(delta_stack, small_delta_stack,
+ sizeof(*delta_stack)*delta_stack_nr);
+ } else {
+ ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
+ }
+ i = delta_stack_nr++;
+ delta_stack[i].obj_offset = obj_offset;
+ delta_stack[i].curpos = curpos;
+ delta_stack[i].size = size;
+
+ curpos = obj_offset = base_offset;
+ }
+
+ /* PHASE 2: handle the base */
+ switch (type) {
+ case OBJ_OFS_DELTA:
+ case OBJ_REF_DELTA:
+ if (data)
+ die("BUG in unpack_entry: left loop at a valid delta");
+ break;
+ case OBJ_COMMIT:
+ case OBJ_TREE:
+ case OBJ_BLOB:
+ case OBJ_TAG:
+ if (!base_from_cache)
+ data = unpack_compressed_entry(p, &w_curs, curpos, size);
+ break;
+ default:
+ data = NULL;
+ error("unknown object type %i at offset %"PRIuMAX" in %s",
+ type, (uintmax_t)obj_offset, p->pack_name);
+ }
+
+ /* PHASE 3: apply deltas in order */
+
+ /* invariants:
+ * 'data' holds the base data, or NULL if there was corruption
+ */
+ while (delta_stack_nr) {
+ void *delta_data;
+ void *base = data;
+ unsigned long delta_size, base_size = size;
+ int i;
+
+ data = NULL;
+
+ if (base)
+ add_delta_base_cache(p, obj_offset, base, base_size, type);
+
+ if (!base) {
+ /*
+ * We're probably in deep shit, but let's try to fetch
+ * the required base anyway from another pack or loose.
+ * This is costly but should happen only in the presence
+ * of a corrupted pack, and is better than failing outright.
+ */
+ struct revindex_entry *revidx;
+ const unsigned char *base_sha1;
+ revidx = find_pack_revindex(p, obj_offset);
+ if (revidx) {
+ base_sha1 = nth_packed_object_sha1(p, revidx->nr);
+ error("failed to read delta base object %s"
+ " at offset %"PRIuMAX" from %s",
+ sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
+ p->pack_name);
+ mark_bad_packed_object(p, base_sha1);
+ base = read_object(base_sha1, &type, &base_size);
+ }
+ }
+
+ i = --delta_stack_nr;
+ obj_offset = delta_stack[i].obj_offset;
+ curpos = delta_stack[i].curpos;
+ delta_size = delta_stack[i].size;
+
+ if (!base)
+ continue;
+
+ delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
+
+ if (!delta_data) {
+ error("failed to unpack compressed delta "
+ "at offset %"PRIuMAX" from %s",
+ (uintmax_t)curpos, p->pack_name);
+ data = NULL;
+ continue;
+ }
+
+ data = patch_delta(base, base_size,
+ delta_data, delta_size,
+ &size);
+
+ /*
+ * We could not apply the delta; warn the user, but keep going.
+ * Our failure will be noticed either in the next iteration of
+ * the loop, or if this is the final delta, in the caller when
+ * we return NULL. Those code paths will take care of making
+ * a more explicit warning and retrying with another copy of
+ * the object.
+ */
+ if (!data)
+ error("failed to apply delta");
+
+ free(delta_data);
+ }
+
+ *final_type = type;
+ *final_size = size;
+
+ unuse_pack(&w_curs);
+
+ if (delta_stack != small_delta_stack)
+ free(delta_stack);
+
+ return data;
+}
+
+const unsigned char *nth_packed_object_sha1(struct packed_git *p,
+ uint32_t n)
+{
+ const unsigned char *index = p->index_data;
+ if (!index) {
+ if (open_pack_index(p))
+ return NULL;
+ index = p->index_data;
+ }
+ if (n >= p->num_objects)
+ return NULL;
+ index += 4 * 256;
+ if (p->index_version == 1) {
+ return index + 24 * n + 4;
+ } else {
+ index += 8;
+ return index + 20 * n;
+ }
+}
+
+off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
+{
+ const unsigned char *index = p->index_data;
+ index += 4 * 256;
+ if (p->index_version == 1) {
+ return ntohl(*((uint32_t *)(index + 24 * n)));
+ } else {
+ uint32_t off;
+ index += 8 + p->num_objects * (20 + 4);
+ off = ntohl(*((uint32_t *)(index + 4 * n)));
+ if (!(off & 0x80000000))
+ return off;
+ index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+ return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
+ ntohl(*((uint32_t *)(index + 4)));
+ }
+}
+
+off_t find_pack_entry_one(const unsigned char *sha1,
+ struct packed_git *p)
+{
+ const uint32_t *level1_ofs = p->index_data;
+ const unsigned char *index = p->index_data;
+ unsigned hi, lo, stride;
+ static int use_lookup = -1;
+ static int debug_lookup = -1;
+
+ if (debug_lookup < 0)
+ debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
+
+ if (!index) {
+ if (open_pack_index(p))
+ return 0;
+ level1_ofs = p->index_data;
+ index = p->index_data;
+ }
+ if (p->index_version > 1) {
+ level1_ofs += 2;
+ index += 8;
+ }
+ index += 4 * 256;
+ hi = ntohl(level1_ofs[*sha1]);
+ lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
+ if (p->index_version > 1) {
+ stride = 20;
+ } else {
+ stride = 24;
+ index += 4;
+ }
+
+ if (debug_lookup)
+ printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
+ sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
+
+ if (use_lookup < 0)
+ use_lookup = !!getenv("GIT_USE_LOOKUP");
+ if (use_lookup) {
+ int pos = sha1_entry_pos(index, stride, 0,
+ lo, hi, p->num_objects, sha1);
+ if (pos < 0)
+ return 0;
+ return nth_packed_object_offset(p, pos);
+ }
+
+ do {
+ unsigned mi = (lo + hi) / 2;
+ int cmp = hashcmp(index + mi * stride, sha1);
+
+ if (debug_lookup)
+ printf("lo %u hi %u rg %u mi %u\n",
+ lo, hi, hi - lo, mi);
+ if (!cmp)
+ return nth_packed_object_offset(p, mi);
+ if (cmp > 0)
+ hi = mi;
+ else
+ lo = mi+1;
+ } while (lo < hi);
+ return 0;
+}
+
+int is_pack_valid(struct packed_git *p)
+{
+ /* An already open pack is known to be valid. */
+ if (p->pack_fd != -1)
+ return 1;
+
+ /* If the pack has one window completely covering the
+ * file size, the pack is known to be valid even if
+ * the descriptor is not currently open.
+ */
+ if (p->windows) {
+ struct pack_window *w = p->windows;
+
+ if (!w->offset && w->len == p->pack_size)
+ return 1;
+ }
+
+ /* Force the pack to open to prove its valid. */
+ return !open_packed_git(p);
+}
+
+static int fill_pack_entry(const unsigned char *sha1,
+ struct pack_entry *e,
+ struct packed_git *p)
+{
+ off_t offset;
+
+ if (p->num_bad_objects) {
+ unsigned i;
+ for (i = 0; i < p->num_bad_objects; i++)
+ if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
+ return 0;
+ }
+
+ offset = find_pack_entry_one(sha1, p);
+ if (!offset)
+ return 0;
+
+ /*
+ * We are about to tell the caller where they can locate the
+ * requested object. We better make sure the packfile is
+ * still here and can be accessed before supplying that
+ * answer, as it may have been deleted since the index was
+ * loaded!
+ */
+ if (!is_pack_valid(p))
+ return 0;
+ e->offset = offset;
+ e->p = p;
+ hashcpy(e->sha1, sha1);
+ return 1;
+}
+
+/*
+ * Iff a pack file contains the object named by sha1, return true and
+ * store its location to e.
+ */
+static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
+{
+ struct packed_git *p;
+
+ prepare_packed_git();
+ if (!packed_git)
+ return 0;
+
+ if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
+ return 1;
+
+ for (p = packed_git; p; p = p->next) {
+ if (p == last_found_pack)
+ continue; /* we already checked this one */
+
+ if (fill_pack_entry(sha1, e, p)) {
+ last_found_pack = p;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+struct packed_git *find_sha1_pack(const unsigned char *sha1,
+ struct packed_git *packs)
+{
+ struct packed_git *p;
+
+ for (p = packs; p; p = p->next) {
+ if (find_pack_entry_one(sha1, p))
+ return p;
+ }
+ return NULL;
+
+}
+
+static int sha1_loose_object_info(const unsigned char *sha1,
+ struct object_info *oi,
+ int flags)
+{
+ int status = 0;
+ unsigned long mapsize;
+ void *map;
+ git_zstream stream;
+ char hdr[32];
+ struct strbuf hdrbuf = STRBUF_INIT;
+
+ if (oi->delta_base_sha1)
+ hashclr(oi->delta_base_sha1);
+
+ /*
+ * If we don't care about type or size, then we don't
+ * need to look inside the object at all. Note that we
+ * do not optimize out the stat call, even if the
+ * caller doesn't care about the disk-size, since our
+ * return value implicitly indicates whether the
+ * object even exists.
+ */
+ if (!oi->typep && !oi->typename && !oi->sizep) {
+ struct stat st;
+ if (stat_sha1_file(sha1, &st) < 0)
+ return -1;
+ if (oi->disk_sizep)
+ *oi->disk_sizep = st.st_size;
+ return 0;
+ }
+
+ map = map_sha1_file(sha1, &mapsize);
+ if (!map)
+ return -1;
+ if (oi->disk_sizep)
+ *oi->disk_sizep = mapsize;
+ if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
+ if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+ status = error("unable to unpack %s header with --allow-unknown-type",
+ sha1_to_hex(sha1));
+ } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+ status = error("unable to unpack %s header",
+ sha1_to_hex(sha1));
+ if (status < 0)
+ ; /* Do nothing */
+ else if (hdrbuf.len) {
+ if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
+ status = error("unable to parse %s header with --allow-unknown-type",
+ sha1_to_hex(sha1));
+ } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
+ status = error("unable to parse %s header", sha1_to_hex(sha1));
+ git_inflate_end(&stream);
+ munmap(map, mapsize);
+ if (status && oi->typep)
+ *oi->typep = status;
+ strbuf_release(&hdrbuf);
+ return 0;
+}
+
+int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
+{
+ struct cached_object *co;
+ struct pack_entry e;
+ int rtype;
+ enum object_type real_type;
+ const unsigned char *real = lookup_replace_object_extended(sha1, flags);
+
+ co = find_cached_object(real);
+ if (co) {
+ if (oi->typep)
+ *(oi->typep) = co->type;
+ if (oi->sizep)
+ *(oi->sizep) = co->size;
+ if (oi->disk_sizep)
+ *(oi->disk_sizep) = 0;
+ if (oi->delta_base_sha1)
+ hashclr(oi->delta_base_sha1);
+ if (oi->typename)
+ strbuf_addstr(oi->typename, typename(co->type));
+ oi->whence = OI_CACHED;
+ return 0;
+ }
+
+ if (!find_pack_entry(real, &e)) {
+ /* Most likely it's a loose object. */
+ if (!sha1_loose_object_info(real, oi, flags)) {
+ oi->whence = OI_LOOSE;
+ return 0;
+ }
+
+ /* Not a loose object; someone else may have just packed it. */
+ reprepare_packed_git();
+ if (!find_pack_entry(real, &e))
+ return -1;
+ }
+
+ /*
+ * packed_object_info() does not follow the delta chain to
+ * find out the real type, unless it is given oi->typep.
+ */
+ if (oi->typename && !oi->typep)
+ oi->typep = &real_type;
+
+ rtype = packed_object_info(e.p, e.offset, oi);
+ if (rtype < 0) {
+ mark_bad_packed_object(e.p, real);
+ if (oi->typep == &real_type)
+ oi->typep = NULL;
+ return sha1_object_info_extended(real, oi, 0);
+ } else if (in_delta_base_cache(e.p, e.offset)) {
+ oi->whence = OI_DBCACHED;
+ } else {
+ oi->whence = OI_PACKED;
+ oi->u.packed.offset = e.offset;
+ oi->u.packed.pack = e.p;
+ oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
+ rtype == OBJ_OFS_DELTA);
+ }
+ if (oi->typename)
+ strbuf_addstr(oi->typename, typename(*oi->typep));
+ if (oi->typep == &real_type)
+ oi->typep = NULL;
+
+ return 0;
+}
+
+/* returns enum object_type or negative */
+int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
+{
+ enum object_type type;
+ struct object_info oi = {NULL};
+
+ oi.typep = &type;
+ oi.sizep = sizep;
+ if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
+ return -1;
+ return type;
+}
+
+static void *read_packed_sha1(const unsigned char *sha1,
+ enum object_type *type, unsigned long *size)
+{
+ struct pack_entry e;
+ void *data;
+
+ if (!find_pack_entry(sha1, &e))
+ return NULL;
+ data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
+ if (!data) {
+ /*
+ * We're probably in deep shit, but let's try to fetch
+ * the required object anyway from another pack or loose.
+ * This should happen only in the presence of a corrupted
+ * pack, and is better than failing outright.
+ */
+ error("failed to read object %s at offset %"PRIuMAX" from %s",
+ sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
+ mark_bad_packed_object(e.p, sha1);
+ data = read_object(sha1, type, size);
+ }
+ return data;
+}
+
+int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
+ unsigned char *sha1)
+{
+ struct cached_object *co;
+
+ hash_sha1_file(buf, len, typename(type), sha1);
+ if (has_sha1_file(sha1) || find_cached_object(sha1))
+ return 0;
+ ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
+ co = &cached_objects[cached_object_nr++];
+ co->size = len;
+ co->type = type;
+ co->buf = xmalloc(len);
+ memcpy(co->buf, buf, len);
+ hashcpy(co->sha1, sha1);
+ return 0;
+}
+
+static void *read_object(const unsigned char *sha1, enum object_type *type,
+ unsigned long *size)
+{
+ unsigned long mapsize;
+ void *map, *buf;
+ struct cached_object *co;
+
+ co = find_cached_object(sha1);
+ if (co) {
+ *type = co->type;
+ *size = co->size;
+ return xmemdupz(co->buf, co->size);
+ }
+
+ buf = read_packed_sha1(sha1, type, size);
+ if (buf)
+ return buf;
+ map = map_sha1_file(sha1, &mapsize);
+ if (map) {
+ buf = unpack_sha1_file(map, mapsize, type, size, sha1);
+ munmap(map, mapsize);
+ return buf;
+ }
+ reprepare_packed_git();
+ return read_packed_sha1(sha1, type, size);
+}
+
+/*
+ * This function dies on corrupt objects; the callers who want to
+ * deal with them should arrange to call read_object() and give error
+ * messages themselves.
+ */
+void *read_sha1_file_extended(const unsigned char *sha1,
+ enum object_type *type,
+ unsigned long *size,
+ unsigned flag)
+{
+ void *data;
+ const struct packed_git *p;
+ const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
+
+ errno = 0;
+ data = read_object(repl, type, size);
+ if (data)
+ return data;
+
+ if (errno && errno != ENOENT)
+ die_errno("failed to read object %s", sha1_to_hex(sha1));
+
+ /* die if we replaced an object with one that does not exist */
+ if (repl != sha1)
+ die("replacement %s not found for %s",
+ sha1_to_hex(repl), sha1_to_hex(sha1));
+
+ if (has_loose_object(repl)) {
+ const char *path = sha1_file_name(sha1);
+
+ die("loose object %s (stored in %s) is corrupt",
+ sha1_to_hex(repl), path);
+ }
+
+ if ((p = has_packed_and_bad(repl)) != NULL)
+ die("packed object %s (stored in %s) is corrupt",
+ sha1_to_hex(repl), p->pack_name);
+
+ return NULL;
+}
+
+void *read_object_with_reference(const unsigned char *sha1,
+ const char *required_type_name,
+ unsigned long *size,
+ unsigned char *actual_sha1_return)
+{
+ enum object_type type, required_type;
+ void *buffer;
+ unsigned long isize;
+ unsigned char actual_sha1[20];
+
+ required_type = type_from_string(required_type_name);
+ hashcpy(actual_sha1, sha1);
+ while (1) {
+ int ref_length = -1;
+ const char *ref_type = NULL;
+
+ buffer = read_sha1_file(actual_sha1, &type, &isize);
+ if (!buffer)
+ return NULL;
+ if (type == required_type) {
+ *size = isize;
+ if (actual_sha1_return)
+ hashcpy(actual_sha1_return, actual_sha1);
+ return buffer;
+ }
+ /* Handle references */
+ else if (type == OBJ_COMMIT)
+ ref_type = "tree ";
+ else if (type == OBJ_TAG)
+ ref_type = "object ";
+ else {
+ free(buffer);
+ return NULL;
+ }
+ ref_length = strlen(ref_type);
+
+ if (ref_length + 40 > isize ||
+ memcmp(buffer, ref_type, ref_length) ||
+ get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
+ free(buffer);
+ return NULL;
+ }
+ free(buffer);
+ /* Now we have the ID of the referred-to object in
+ * actual_sha1. Check again. */
+ }
+}
+
+static void write_sha1_file_prepare(const void *buf, unsigned long len,
+ const char *type, unsigned char *sha1,
+ char *hdr, int *hdrlen)
+{
+ git_SHA_CTX c;
+
+ /* Generate the header */
+ *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
+
+ /* Sha1.. */
+ git_SHA1_Init(&c);
+ git_SHA1_Update(&c, hdr, *hdrlen);
+ git_SHA1_Update(&c, buf, len);
+ git_SHA1_Final(sha1, &c);
+}
+
+/*
+ * Move the just written object into its final resting place.
+ */
+int finalize_object_file(const char *tmpfile, const char *filename)
+{
+ int ret = 0;
+
+ if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
+ goto try_rename;
+ else if (link(tmpfile, filename))
+ ret = errno;
+
+ /*
+ * Coda hack - coda doesn't like cross-directory links,
+ * so we fall back to a rename, which will mean that it
+ * won't be able to check collisions, but that's not a
+ * big deal.
+ *
+ * The same holds for FAT formatted media.
+ *
+ * When this succeeds, we just return. We have nothing
+ * left to unlink.
+ */
+ if (ret && ret != EEXIST) {
+ try_rename:
+ if (!rename(tmpfile, filename))
+ goto out;
+ ret = errno;
+ }
+ unlink_or_warn(tmpfile);
+ if (ret) {
+ if (ret != EEXIST) {
+ return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
+ }
+ /* FIXME!!! Collision check here ? */
+ }
+
+out:
+ if (adjust_shared_perm(filename))
+ return error("unable to set permission to '%s'", filename);
+ return 0;
+}
+
+static int write_buffer(int fd, const void *buf, size_t len)
+{
+ if (write_in_full(fd, buf, len) < 0)
+ return error("file write error (%s)", strerror(errno));
+ return 0;
+}
+
+int hash_sha1_file(const void *buf, unsigned long len, const char *type,
+ unsigned char *sha1)
+{
+ char hdr[32];
+ int hdrlen;
+ write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+ return 0;
+}
+
+/* Finalize a file on disk, and close it. */
+static void close_sha1_file(int fd)
+{
+ if (fsync_object_files)
+ fsync_or_die(fd, "sha1 file");
+ if (close(fd) != 0)
+ die_errno("error when closing sha1 file");
+}
+
+/* Size of directory component, including the ending '/' */
+static inline int directory_size(const char *filename)
+{
+ const char *s = strrchr(filename, '/');
+ if (!s)
+ return 0;
+ return s - filename + 1;
+}
+
+/*
+ * This creates a temporary file in the same directory as the final
+ * 'filename'
+ *
+ * We want to avoid cross-directory filename renames, because those
+ * can have problems on various filesystems (FAT, NFS, Coda).
+ */
+static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
+{
+ int fd, dirlen = directory_size(filename);
+
+ if (dirlen + 20 > bufsiz) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+ memcpy(buffer, filename, dirlen);
+ strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
+ fd = git_mkstemp_mode(buffer, 0444);
+ if (fd < 0 && dirlen && errno == ENOENT) {
+ /* Make sure the directory exists */
+ memcpy(buffer, filename, dirlen);
+ buffer[dirlen-1] = 0;
+ if (mkdir(buffer, 0777) && errno != EEXIST)
+ return -1;
+ if (adjust_shared_perm(buffer))
+ return -1;
+
+ /* Try again */
+ strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
+ fd = git_mkstemp_mode(buffer, 0444);
+ }
+ return fd;
+}
+
+static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
+ const void *buf, unsigned long len, time_t mtime)
+{
+ int fd, ret;
+ unsigned char compressed[4096];
+ git_zstream stream;
+ git_SHA_CTX c;
+ unsigned char parano_sha1[20];
+ static char tmp_file[PATH_MAX];
+ const char *filename = sha1_file_name(sha1);
+
+ fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
+ if (fd < 0) {
+ if (errno == EACCES)
+ return error("insufficient permission for adding an object to repository database %s", get_object_directory());
+ else
+ return error("unable to create temporary file: %s", strerror(errno));
+ }
+
+ /* Set it up */
+ git_deflate_init(&stream, zlib_compression_level);
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ git_SHA1_Init(&c);
+
+ /* First header.. */
+ stream.next_in = (unsigned char *)hdr;
+ stream.avail_in = hdrlen;
+ while (git_deflate(&stream, 0) == Z_OK)
+ ; /* nothing */
+ git_SHA1_Update(&c, hdr, hdrlen);
+
+ /* Then the data itself.. */
+ stream.next_in = (void *)buf;
+ stream.avail_in = len;
+ do {
+ unsigned char *in0 = stream.next_in;
+ ret = git_deflate(&stream, Z_FINISH);
+ git_SHA1_Update(&c, in0, stream.next_in - in0);
+ if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
+ die("unable to write sha1 file");
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ } while (ret == Z_OK);
+
+ if (ret != Z_STREAM_END)
+ die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
+ ret = git_deflate_end_gently(&stream);
+ if (ret != Z_OK)
+ die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
+ git_SHA1_Final(parano_sha1, &c);
+ if (hashcmp(sha1, parano_sha1) != 0)
+ die("confused by unstable object source data for %s", sha1_to_hex(sha1));
+
+ close_sha1_file(fd);
+
+ if (mtime) {
+ struct utimbuf utb;
+ utb.actime = mtime;
+ utb.modtime = mtime;
+ if (utime(tmp_file, &utb) < 0)
+ warning("failed utime() on %s: %s",
+ tmp_file, strerror(errno));
+ }
+
+ return finalize_object_file(tmp_file, filename);
+}
+
+static int freshen_loose_object(const unsigned char *sha1)
+{
+ return check_and_freshen(sha1, 1);
+}
+
+static int freshen_packed_object(const unsigned char *sha1)
+{
+ struct pack_entry e;
+ if (!find_pack_entry(sha1, &e))
+ return 0;
+ if (e.p->freshened)
+ return 1;
+ if (!freshen_file(e.p->pack_name))
+ return 0;
+ e.p->freshened = 1;
+ return 1;
+}
+
+int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
+{
+ char hdr[32];
+ int hdrlen;
+
+ /* Normally if we have it in the pack then we do not bother writing
+ * it out into .git/objects/??/?{38} file.
+ */
+ write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
+ if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+ return 0;
+ return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
+}
+
+int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
+ unsigned char *sha1, unsigned flags)
+{
+ char *header;
+ int hdrlen, status = 0;
+
+ /* type string, SP, %lu of the length plus NUL must fit this */
+ header = xmalloc(strlen(type) + 32);
+ write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
+
+ if (!(flags & HASH_WRITE_OBJECT))
+ goto cleanup;
+ if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
+ goto cleanup;
+ status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
+
+cleanup:
+ free(header);
+ return status;
+}
+
+int force_object_loose(const unsigned char *sha1, time_t mtime)
+{
+ void *buf;
+ unsigned long len;
+ enum object_type type;
+ char hdr[32];
+ int hdrlen;
+ int ret;
+
+ if (has_loose_object(sha1))
+ return 0;
+ buf = read_packed_sha1(sha1, &type, &len);
+ if (!buf)
+ return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
+ hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
+ ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
+ free(buf);
+
+ return ret;
+}
+
+int has_pack_index(const unsigned char *sha1)
+{
+ struct stat st;
+ if (stat(sha1_pack_index_name(sha1), &st))
+ return 0;
+ return 1;
+}
+
+int has_sha1_pack(const unsigned char *sha1)
+{
+ struct pack_entry e;
+ return find_pack_entry(sha1, &e);
+}
+
+int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
+{
+ struct pack_entry e;
+
+ if (find_pack_entry(sha1, &e))
+ return 1;
+ if (has_loose_object(sha1))
+ return 1;
+ if (flags & HAS_SHA1_QUICK)
+ return 0;
+ reprepare_packed_git();
+ return find_pack_entry(sha1, &e);
+}
+
+static void check_tree(const void *buf, size_t size)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+
+ init_tree_desc(&desc, buf, size);
+ while (tree_entry(&desc, &entry))
+ /* do nothing
+ * tree_entry() will die() on malformed entries */
+ ;
+}
+
+static void check_commit(const void *buf, size_t size)
+{
+ struct commit c;
+ memset(&c, 0, sizeof(c));
+ if (parse_commit_buffer(&c, buf, size))
+ die("corrupt commit");
+}
+
+static void check_tag(const void *buf, size_t size)
+{
+ struct tag t;
+ memset(&t, 0, sizeof(t));
+ if (parse_tag_buffer(&t, buf, size))
+ die("corrupt tag");
+}
+
+static int index_mem(unsigned char *sha1, void *buf, size_t size,
+ enum object_type type,
+ const char *path, unsigned flags)
+{
+ int ret, re_allocated = 0;
+ int write_object = flags & HASH_WRITE_OBJECT;
+
+ if (!type)
+ type = OBJ_BLOB;
+
+ /*
+ * Convert blobs to git internal format
+ */
+ if ((type == OBJ_BLOB) && path) {
+ struct strbuf nbuf = STRBUF_INIT;
+ if (convert_to_git(path, buf, size, &nbuf,
+ write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
+ buf = strbuf_detach(&nbuf, &size);
+ re_allocated = 1;
+ }
+ }
+ if (flags & HASH_FORMAT_CHECK) {
+ if (type == OBJ_TREE)
+ check_tree(buf, size);
+ if (type == OBJ_COMMIT)
+ check_commit(buf, size);
+ if (type == OBJ_TAG)
+ check_tag(buf, size);
+ }
+
+ if (write_object)
+ ret = write_sha1_file(buf, size, typename(type), sha1);
+ else
+ ret = hash_sha1_file(buf, size, typename(type), sha1);
+ if (re_allocated)
+ free(buf);
+ return ret;
+}
+
+static int index_stream_convert_blob(unsigned char *sha1, int fd,
+ const char *path, unsigned flags)
+{
+ int ret;
+ const int write_object = flags & HASH_WRITE_OBJECT;
+ struct strbuf sbuf = STRBUF_INIT;
+
+ assert(path);
+ assert(would_convert_to_git_filter_fd(path));
+
+ convert_to_git_filter_fd(path, fd, &sbuf,
+ write_object ? safe_crlf : SAFE_CRLF_FALSE);
+
+ if (write_object)
+ ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+ sha1);
+ else
+ ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
+ sha1);
+ strbuf_release(&sbuf);
+ return ret;
+}
+
+static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
+ const char *path, unsigned flags)
+{
+ struct strbuf sbuf = STRBUF_INIT;
+ int ret;
+
+ if (strbuf_read(&sbuf, fd, 4096) >= 0)
+ ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
+ else
+ ret = -1;
+ strbuf_release(&sbuf);
+ return ret;
+}
+
+#define SMALL_FILE_SIZE (32*1024)
+
+static int index_core(unsigned char *sha1, int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags)
+{
+ int ret;
+
+ if (!size) {
+ ret = index_mem(sha1, "", size, type, path, flags);
+ } else if (size <= SMALL_FILE_SIZE) {
+ char *buf = xmalloc(size);
+ if (size == read_in_full(fd, buf, size))
+ ret = index_mem(sha1, buf, size, type, path, flags);
+ else
+ ret = error("short read %s", strerror(errno));
+ free(buf);
+ } else {
+ void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ ret = index_mem(sha1, buf, size, type, path, flags);
+ munmap(buf, size);
+ }
+ return ret;
+}
+
+/*
+ * This creates one packfile per large blob unless bulk-checkin
+ * machinery is "plugged".
+ *
+ * This also bypasses the usual "convert-to-git" dance, and that is on
+ * purpose. We could write a streaming version of the converting
+ * functions and insert that before feeding the data to fast-import
+ * (or equivalent in-core API described above). However, that is
+ * somewhat complicated, as we do not know the size of the filter
+ * result, which we need to know beforehand when writing a git object.
+ * Since the primary motivation for trying to stream from the working
+ * tree file and to avoid mmaping it in core is to deal with large
+ * binary blobs, they generally do not want to get any conversion, and
+ * callers should avoid this code path when filters are requested.
+ */
+static int index_stream(unsigned char *sha1, int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags)
+{
+ return index_bulk_checkin(sha1, fd, size, type, path, flags);
+}
+
+int index_fd(unsigned char *sha1, int fd, struct stat *st,
+ enum object_type type, const char *path, unsigned flags)
+{
+ int ret;
+
+ /*
+ * Call xsize_t() only when needed to avoid potentially unnecessary
+ * die() for large files.
+ */
+ if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
+ ret = index_stream_convert_blob(sha1, fd, path, flags);
+ else if (!S_ISREG(st->st_mode))
+ ret = index_pipe(sha1, fd, type, path, flags);
+ else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
+ (path && would_convert_to_git(path)))
+ ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
+ flags);
+ else
+ ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
+ flags);
+ close(fd);
+ return ret;
+}
+
+int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
+{
+ int fd;
+ struct strbuf sb = STRBUF_INIT;
+
+ switch (st->st_mode & S_IFMT) {
+ case S_IFREG:
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return error("open(\"%s\"): %s", path,
+ strerror(errno));
+ if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
+ return error("%s: failed to insert into database",
+ path);
+ break;
+ case S_IFLNK:
+ if (strbuf_readlink(&sb, path, st->st_size)) {
+ char *errstr = strerror(errno);
+ return error("readlink(\"%s\"): %s", path,
+ errstr);
+ }
+ if (!(flags & HASH_WRITE_OBJECT))
+ hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
+ else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
+ return error("%s: failed to insert into database",
+ path);
+ strbuf_release(&sb);
+ break;
+ case S_IFDIR:
+ return resolve_gitlink_ref(path, "HEAD", sha1);
+ default:
+ return error("%s: unsupported file type", path);
+ }
+ return 0;
+}
+
+int read_pack_header(int fd, struct pack_header *header)
+{
+ if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
+ /* "eof before pack header was fully read" */
+ return PH_ERROR_EOF;
+
+ if (header->hdr_signature != htonl(PACK_SIGNATURE))
+ /* "protocol error (pack signature mismatch detected)" */
+ return PH_ERROR_PACK_SIGNATURE;
+ if (!pack_version_ok(header->hdr_version))
+ /* "protocol error (pack version unsupported)" */
+ return PH_ERROR_PROTOCOL;
+ return 0;
+}
+
+void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
+{
+ enum object_type type = sha1_object_info(sha1, NULL);
+ if (type < 0)
+ die("%s is not a valid object", sha1_to_hex(sha1));
+ if (type != expect)
+ die("%s is not a valid '%s' object", sha1_to_hex(sha1),
+ typename(expect));
+}
+
+static int for_each_file_in_obj_subdir(int subdir_nr,
+ struct strbuf *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ size_t baselen = path->len;
+ DIR *dir = opendir(path->buf);
+ struct dirent *de;
+ int r = 0;
+
+ if (!dir) {
+ if (errno == ENOENT)
+ return 0;
+ return error("unable to open %s: %s", path->buf, strerror(errno));
+ }
+
+ while ((de = readdir(dir))) {
+ if (is_dot_or_dotdot(de->d_name))
+ continue;
+
+ strbuf_setlen(path, baselen);
+ strbuf_addf(path, "/%s", de->d_name);
+
+ if (strlen(de->d_name) == 38) {
+ char hex[41];
+ unsigned char sha1[20];
+
+ snprintf(hex, sizeof(hex), "%02x%s",
+ subdir_nr, de->d_name);
+ if (!get_sha1_hex(hex, sha1)) {
+ if (obj_cb) {
+ r = obj_cb(sha1, path->buf, data);
+ if (r)
+ break;
+ }
+ continue;
+ }
+ }
+
+ if (cruft_cb) {
+ r = cruft_cb(de->d_name, path->buf, data);
+ if (r)
+ break;
+ }
+ }
+ strbuf_setlen(path, baselen);
+
+ if (!r && subdir_cb)
+ r = subdir_cb(subdir_nr, path->buf, data);
+
+ closedir(dir);
+ return r;
+}
+
+int for_each_loose_file_in_objdir_buf(struct strbuf *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ size_t baselen = path->len;
+ int r = 0;
+ int i;
+
+ for (i = 0; i < 256; i++) {
+ strbuf_addf(path, "/%02x", i);
+ r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
+ subdir_cb, data);
+ strbuf_setlen(path, baselen);
+ if (r)
+ break;
+ }
+
+ return r;
+}
+
+int for_each_loose_file_in_objdir(const char *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ struct strbuf buf = STRBUF_INIT;
+ int r;
+
+ strbuf_addstr(&buf, path);
+ r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
+ subdir_cb, data);
+ strbuf_release(&buf);
+
+ return r;
+}
+
+struct loose_alt_odb_data {
+ each_loose_object_fn *cb;
+ void *data;
+};
+
+static int loose_from_alt_odb(struct alternate_object_database *alt,
+ void *vdata)
+{
+ struct loose_alt_odb_data *data = vdata;
+ struct strbuf buf = STRBUF_INIT;
+ int r;
+
+ /* copy base not including trailing '/' */
+ strbuf_add(&buf, alt->base, alt->name - alt->base - 1);
+ r = for_each_loose_file_in_objdir_buf(&buf,
+ data->cb, NULL, NULL,
+ data->data);
+ strbuf_release(&buf);
+ return r;
+}
+
+int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
+{
+ struct loose_alt_odb_data alt;
+ int r;
+
+ r = for_each_loose_file_in_objdir(get_object_directory(),
+ cb, NULL, NULL, data);
+ if (r)
+ return r;
+
+ if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
+ return 0;
+
+ alt.cb = cb;
+ alt.data = data;
+ return foreach_alt_odb(loose_from_alt_odb, &alt);
+}
+
+static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
+{
+ uint32_t i;
+ int r = 0;
+
+ for (i = 0; i < p->num_objects; i++) {
+ const unsigned char *sha1 = nth_packed_object_sha1(p, i);
+
+ if (!sha1)
+ return error("unable to get sha1 of object %u in %s",
+ i, p->pack_name);
+
+ r = cb(sha1, p, i, data);
+ if (r)
+ break;
+ }
+ return r;
+}
+
+int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
+{
+ struct packed_git *p;
+ int r = 0;
+ int pack_errors = 0;
+
+ prepare_packed_git();
+ for (p = packed_git; p; p = p->next) {
+ if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
+ continue;
+ if (open_pack_index(p)) {
+ pack_errors = 1;
+ continue;
+ }
+ r = for_each_object_in_pack(p, cb, data);
+ if (r)
+ break;
+ }
+ return r ? r : pack_errors;
+}